From: Pablo Neira Ayuso pablo@netfilter.org
[ Upstream commit 84b3268027641401bb8ad4427a90a3cce2eb86f5 ]
Userspace might send a batch that is composed of several netlink messages. The netlink_ack() function must use the pointer to the netlink header as base to calculate the bad attribute offset.
Fixes: 2d4bc93368f5 ("netlink: extended ACK reporting") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/af_netlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2434,7 +2434,7 @@ void netlink_ack(struct sk_buff *in_skb, in_skb->len)) WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, (u8 *)extack->bad_attr - - in_skb->data)); + (u8 *)nlh)); } else { if (extack->cookie_len) WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,